Electronic direction circuit



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wma "mnemonic nnincrroN John L Bower, Downey, Calif., assigner to American Aviation, Inc. Appunti@ Mann z, ress s'ernt No. 569,209.

' u claim. (ct. s4o--.11o

. This invention relates to an electronic prov iding an analysis of input signals and providing an indication of the concurrence of predetermined values this device is adapted to receive digital signals from a plurality of transducers and provide at its output signals North'i' :damien cima;

ig.14 is one possible logical me s is a me @connaissances-pr also. f

rcction circuit', f l

Fig. 6 illustrates another' possible mechanizaiion t the direction circuit and dip-hops, Vin a transrstonned version;

Fig. 7 illustrates heads; und

Fig. 8 illustrates three square wayes.

signnsprsdueea Si' :afee magnetic Fig. 1 illustrates a common method of'generation of l a signal from which must be obtained both quantity and sen'se. A xed member 1 has recorded thereon a mags netic track 1, which cooperates with magnetic reading' heads 3 and 4 to provide signals to tiipflops 5 and 6',

which providefin turn, signals to direction circuit 7,

and changes in values of said signals. More specically, v

representing the'quantity indicated by said transducers and the sense of the quantity indicated. An electrical signal may be analogue in form, that l An elec trical signal may also be digital in form, that is, it is variable only in discrete, readily-distinguishable steps or pulses. The advantagcof digital signals over analogue signals lies in certainty ot distinguishntent between successive steps or qualities. However, one shortcoming of n digital system is that it lacks information between successive digital increments. that many digital systems are not easily adapted to provide anlindication of sense. f

This invention is a circuit capable of receiving digital signals representing a quantity such as motion and provide an output digital signal from which .can be deterruined the amount of motion and the sense (direction Another shortcoming is of motion). In addition, this device provides anv in i creased resolution, effecting an indication of motion with' greater resolution than the resolution of its signals; As a result, an accuracy considerably greater than the customary accuracy of a similar digital system is obtained. It is therefore an object of this invention to provide a digital electroniccircuit providing increased accuracy in indicatiom v lt is another object of this invention tol provide an electronic circuit capable of analyzing electrical signals to obtain information contained therein.l

Another object of this invention is to provide an elec- 'tronic circuit responsive to the concurrence .of predetermined values of' a digital signal and changes in values of a digital signal to provide an indication thereof.

which provides signals to a reversible. digital counter 8.

Heads 3 and 4 are indicated as being spaced an odd number (N) quarter 4vv'svel'eugths apart, where lt is the vvavelength of the recording on track 2.' These magnetic waves may be recorded as many as thousand to the inch. It s desirable that in digital counter 8 be recorded the distance heads 3 electrical signals such as illustrated in Fig. Z, A and B,

are generated by the heads 3 and 4, respectively.- It is noted thanwavc: A and B are displacedA in phase according to thedistance of displacement between heads. 3

and 4 and in both Figsrl and 2 this can be seen to an odd number o f quarter wavelengths.

The sine'wave signals of Fig. 2 are received by tlip-ops S .and 6 and .are converted to' the square waves illus. trated in Fig. 3'as c and which also are displaced in v phase an odd number of quarter wavelengths. The sig 7 of Fig. l receives the outputs of dip-deps 5 and 6 and stm @other object of this invention is to provide mi electronic circuit receiving a plurality of input digital y signals and provide an output in accordance with thc relative values of said digital determines from the information (illustrated in Fig. 3),

the motion and direction of Athe motion of magnetic heads 3 and 4 along track 2. It may be readily understood that curvilinear motion may be involved as well as rectilinear motion.

Assuming that heads 3 and 4 are inoving with respect i to inemhcr 1, we may consider in Fig. 3 that motion is occurring, for example, to the right,.rnoving along the A still further obim of invention is to provide anY n electronic circuit which receives signals representing a quantity such as motion and direction of motion and provides an output signal in digital form representing a quantity such as motion'and direction of motion.

Other objects of invention will become apparent from the following description taken in connection with the ferre'dinto digital forni by a device such as a ip-op;

square wave. It may be appreciatedirom Fig. 3 that l' the terms e and represent idealized values of the values of waves A and B as might he provided, for example,

by iipdlops in response to waves A and B.

A logical equation indicating motion to the right may be written as' follows: y

dicates change from to and a' indicates-change from a' toa and b indicates change from p to Equation mechanizationofthe;

v(1)' lett rnaybe represented -as t'ollowsz 'i l received on one line and additional line or lines 'i epesses 62. These diodes are, of course, indicating motion to the being received on line 77 should be subtracted.A The ba :e

ing, at which time, point 8S becomes morepositive and provides an output signal at terminal 86 indicating to the counter that the pulses at terminal 77 represent' motion to left.' If a' pulse is received through any of these diodes,

transistor 80 ceases conducting, transistor 79 commences i conducting, and point 82 becomes mre positive providing'A an output voltage to'terminal 83 which indicates a motion to the left and Iindicates to the counter that the pulses then ing the change in each of said signals from one of said values to the other, means for providing signals in respons to the concurrence of a predetermined combination of n signal representing a change-in one channel and the digital u..

value of the received signals in the remaining channels, and counter means responsive yto the output count of said means for providing signals.

the right and are to be added. It wl be noted that this method v.of handling all the pulses on one line and providf' ing a direction signal on the other line is another form of 'handling the same information. can be :een from Fig-6, transformation from one form (where pulses on indicate the opposite) to the other (where all pulses are indicate addition or subtraction) is relatively easy. l

It is apparent that, from the analysis of Figs. 2 and 3, mc:e magnetic heads might be used in which a' third Wave C is combined with waves A and B, as shown in Pig. 7.

` l/bereits, in the illustration of Fig. 2, waves e :hd are 90 electrical degrees apart, the waves would be, using three` heads, 60 degrees :.part. This would mean that the three transducer heads are eachlocated 60 electrical degrees The square waves of Fig. 3 would represent the output of .three ip-ops each connected to a respective magnetic head. The flip-flop outputs would likewise be square f waves a, and 7, each 60 electrical degrees apart, as'

Mechanization of the equation may then be accomplished according to the teaching of Figs. 4, 5 and 6 providing from the others or some multiple of that distance apart to provide a signal 60 electrical degrees from the other waves.

outputs to a counter. The resolution by such mechanization is increased by'the use of threeheads.'

The novel ,concept mechanized hcrm'ul is that from the use of .multiple heads up to 'an indefinite number repre 'sented by the letter N, or the Greek letter u, and the use of devices detecting the changes in outputs, indicatioraof V motion to a greater resolution can be obtained, aswell as indication of the direction of the motion.

be taken'by way of limitation, the spirit and scope of this invention being limited only by the terms of the appended claims,

I claim:

i l. In a digital circuit, whereinvsgnals are received having la plurality of digital values, d iterentiating means for detecting the change iny cach of said signals from one of said values to the other, means for providing signals 'in response to the concurrence of a. predetermined combination of digital values of certain gf said received signals and the changes in the other of said signals, and counter' means responsive to the output count of said means for providing signals.

a The combination recited mentar/wherein said signals are of lxed phase with respect toeach others- 3. .In a binary, digital circuit, wherein signals are rei ceived in a plurality of channels, each. signal having a first' value or a -second value, dierentiatin'g means for detect- 75l ond value to its rst value, gating means providing Sismi!! 4. -In a digital circuit, a plurality of signal channels for receiving aplurality of signals having at least a first value and a second value, electrical dirediiatirfg means con nested in each said channel providing a 'signal indicating the change of said received signals from one of said values to the other, signal gating means connected to be cnntrolled by selected combinations of the outputs of said ditierentiatingmens' and the values of said signal chennels, and counter means responsive to the output count of said signal gating means.

5. In a' digital circuit, a plurality of .signal channels for receiving a plurality of signals having at least a first value and a second value; differentiating means connected in each said channelv providing a signal representing the changein value of said received signals in said channels fr'oin one of said values to the other, signal gating means connected tobe controlled by selected combinations ci f .a the outputs of said ditferentiating means in said channel values of saidv signals in the remaining channels,

and the and counter means responsive tothe output count of said signal gating means. Y

6. ln a digital circuit, a plurality of channels for receivL ing a plurality of input digital signals, a similar plurality of differentiating means as said plurality of channels, each said dicrentiaring means connected in a respective channel, a plurality of gating means each connected to gate the output of a respective differentiating mcans,. said gating means connected to be controlled by selected input signals l .to said channels, and counter means responsive to the output count of said gating means.

7. in a digital circuit, a plurality or flip-deps each adapted to receive an input signal, a plurality of diterentiating means each connected to receivcthe output of said dip-flops. and provide a differentiated output of each of said tlip-tlops, a plurality of gating means each connected e. I

to gate the output of a respective differentiating means of the output of said flip-Hops, said gating means connected to be controlled by selected outputs of -said flip-hops, and

counter means' responsive to the output' count of said gating means. y

8. In adigital circuit wherein input signals are received having a plurality of digital values', electrical diierentiat# ing means for detecting each change in said input signals from one o f said values to the other, electrical gating means providing signals in response to the concurrence of predetermined combinations of values of said input` `signals and the outputs of said electrical differentiating means, and counter means responsive to the outputcount of said electrical gating means.

'electrical differentiating means, said dierentiating means connected to provide a dierentiated output of each of said flip-hops, a plurality of signal gating means each coni nected to gate the output of a respectiveelectrical dileren controlled by -selected outputs of the remainder of said ilip-ops, and counter means responsive to the output count of said signal gating means.

l 10. ln a digital, binary circuit wherein a plurality of signals are received, each ofsaidsignals having a first 4value representedas A N, and a second vdue represented as Af N', diderentiating circuit means for detecting the change, represented as a' n', ofeach of said signals from its first value to its second value, and dierentiating circuit means for detecting the change, represented as a n, of each of said signals from its sec- 9. ln a binary, digital circuit, a plurality of ip-cps,' each adapted to receive an input signal, a plurality of upon the concurrence o predeterniined combinations of,

said change' signals a '1, and a.' n,' and said A N and said A' N' signal values, and counter 11. The combination recited in claim 10 wherein said gating means. provides a signal, R, indicating the prede'- termined combination of signals represented in logren!I equation notation 2s; f

. and said gating means provdcsa signal, L, indicating the means responsive to the oitput countof said gating means.A

predetermined combination of signals represented in logii cal equation notztion"ns:'

L=cb+a'+c'b'+a wherein the characters a and represent idealized vaines of the values of 'signals A and B, respectively, wherein B represents one of the plurality of signals. included inthe seriesA.. .N; l t' 12. In a digital circuit, rst and second iipiops, first and second dierentiating means connected to the first terminal of the first of said ip-fiops, third and fourth diffesentiating means connected to. the lsecond terminal of v said first flipltlop, fifth and sixth di'erenti'ating means connested to the first terminal of said second dip-50p, seventh and eighth di'ercntiating means connected to the second` terminal o f said second dip-dop, first gating means connected to gate the output of said rst differentiating means, said tirst gating means connected to he controlled by the output of 'the second terminal of said second dip-Hop, second gating means connected to gate the output of said second differentiating means, said second gating means IS, i

connected tohe controlled by the output of the terminal of 5am-second einem, third sans; means con.

nected to gate the output of said third diii'erentiating A means, said third gatiiig means connected to be controlled hy the output ofthe first terminal of said second tip-dop,

fourth gating means connected to' gate the output of. said fourth differentiating means, said fourth gating means connected to be controlled by the output of the second terminal of said second dip-Hop, tifth gating means conneeted to gate the output of said tifth diierentiating means,

said fifth gating means connected to be controlled by the output of the rst ate'mzlinal of said rst Hip-flop, sixth gat ing means connected to receive the output of said sixth dif terentiating means, said sixth gating means connected'to be controlled by the output of the second terminal of said first Hip-dop, seventh gatng'means to gate the output of said seventh diterentiating rneans, said seventh gating means' connected to be controlled by the output of the second tennnal of said rst dip-hcp, eighth gating means connected to receive the output of said eighth di5erentiating means, said eighth gating means connected 1o be controlled by the output of the rst terminal of said first iptlop, and counter means connected vto receive the output count of said gating meansnanterre@ ossea in :be me of uns patent .UNrrEo STATES PATENTS 2,685,082 i Benton et al. July 27, 1954 2,717,987 Hagen Sept. 13, 1955 2,733,431 Steele Jan. S'I, 195 2,774,957 Towncr Dee. 18, 1956 oneven Apr. 9, 1957 l 

